Organ chord switch



Sept. 13, 1965 L. J. HAVILAND ORGAN CHORD SWITCH 5 Sheets5heet 1 Filed July 20, 1964 i DIMIN/SHED a? 22/! N VE ZVTOR 222m BY Sept- 3, 1966 L. J. HAVILAND 3,272,058

ORGAN CHORD SWITCH Filed July 20, 1964 5 Sheets-Sheet 2 .D MAJOR D 5EVENT/l D MIA/0E Db pun/1w 51/50 fm/eafor W .Hm/i/mzd j? awxm m Sept. 13, 1966 L. .1 HAVILAND 3,272,053

ORGAN CHORD SWITCH Filed July 20, 1964 5 Sheets-Sheet United States Patent ware Filed July 20, 1964, Ser. No. 383,725 Claims. (Cl. 84-443) This invention relates generally to controls for musical instruments having generating systems for producing electrical tone signals, and relates particularly to a musical chord selecting mechanism having a plurality of manually operable switch elements to control the production of complete chords of preselected tones. The chord selecting mechanism of this invention may constitute one of the cooperating parts of a complete electrical musical instrument, such as that described in United States Patent No 2,645,968, to Hanert, or any other electrical musical instrument which produces electrical tone signals in the number and frequency relationship necessary for producing the number of chords required of the chord selecting mechanism.

It is a broad object of this invention to provide a switching mechanism of simple and durable construction for controlling the tone signal circuits of an electrical musical instrument whereby several electrical tone signals from a plurality of generating sources may be combined and furnished to an output system to produce a musical chord.

A further object is to provide a chord selecting switch mechanism in accordance with the foregoing object, wherein a major proportion of the component parts is made of a relatively small number of groups of identical pieces, which pieces comprise stampings or molded members of simple and inexpensive manufacture and adapted for easy assembly, whereby the switching mechanism may be economically fabricated.

Other objects and advantages of this invention will be apparent from the following description of a presently preferred embodiment thereof, taken in conjunction with the accompanying drawings in which like numerals refer to the same or identical parts in all of the figures, and in which:

FIG. 1 is a top plan view of a keyboard of chord selecting buttons used for actuating the switching mechanism of the present invention;

FIG. 2 is a bottom view of the device shown in FIG. 1;

FIG. 3 is a vertical sectional view of the switching mechanism taken generally on the line 3-3 of FIG. 1, this view showing the switch actuators all in retracted, passive position;

FIG. 4 is a view similar to FIG. 3 but showing one of the switch actuators in its advanced position, bringing several tone signal-carrying spring contact members into contact with their respective bus bars;

FIG. 5 is a fragmentary sectional view taken on the line 55 of FIG. 4, showing a detail of construction of the present switching mechanism;

FIG. 6 is a partial vertical sectional view taken general- 1y on the line 66 of FIG. 3;

FIG. 7 is a partial vertical sectional view taken generally on the line 7--7 of FIG. 3;

FIG. 8 is a vertical sectional view taken generally on the line 8-8 of FIG. 3;

FIG. 9 is a vertical sectional view taken generally on the line 99 of FIG. 3;

FIG. 10 is a partial horizontal sectional view taken generally on the line 1010 of FIG. 9; and

FIG. 11 is a schematic view illustrating wiring for bringing electrical tone signals to the spring contact members, and depicting a representative switch actuator operated by one of the chord selecting buttons, for effecting contact between several of such contact members and their respective bus bars.

Referring now to the drawings, it will be seen that the illustrated embodiment of the present chord selecting switching mechanism includes an accordion type button keyboard 10 comprising forty-eight chord selecting buttons 12 which are manually operated in the manner of accordion chord and bass buttons. The button keyboard is adapted to be fitted into and attached to an organ console to the left of the manual keyboard, as shown in the above mentioned Hanert patent, and includes a molded plastic keyboard plate 14 having forty-eight openings therein for accommodating the chord buttons 12, the latter being arranged in four horizontal rows and twelve vertical rows. In this embodiment, the horizontal rows of buttons are marked with the chord designations Major, Minor, Seventh, and Diminished, and the vertical rows of buttons are marked with the key letter designations Db, Ab, Eb, Bb, F, C, G, D, A, E, B and F#. For convenience, fiatted notes are herein written as the note followed by the letter b, as in the preceding sentence.

As will appear more fully hereinafter, electrical tone signals are supplied to leaf spring contact members associated with each of said chord buttons, and bus bars are provided to conduct electrical tone signals collectively from such contact members to the electroacoustical translating output system of the instrument, so that a major, minor, seventh, or diminished chord in any key may be played through such output system. The electrical circuitry associated with the present device, including the distribution of particular electrical tone signals to particular spring contact members in each group of the latter associated with the respective chord buttons, and including the collection and further distribution of tone signals from the spring contact members to the output system, does not constitute part of the present invention, but comprises the subject matter of the copending application of Alan C. Young, Serial No. 383,728, filed July 20, 1964, and assigned to the assignee of the present application.

By way of a preliminary general discussion, it is to be noted that the present chord switching mechanism includes twelve stacks or banks of leaf spring contact members, later to be described, each stack being disposed below a row of four chord buttons 12 representing respectively the major, minor, seventh and diminished chords of a particular key. Each such row of chord buttons is thus adapted to control the positions of spring contact members in the stack or bank beneath it.

In the illustrated embodiment each stack contains six such spring contact members, but it will be understood that more or fewer contact springs may be used in such stacks, if desired, to permit the playing of more or fewer chords, and in such cases the number of horizontal rows of chord buttons 12 would be correspondingly increased or reduced. The stacks of spring contact members are preferably assembled in three separate groups or units, each consisting of four such stacks, one such group being shown generally as 16 in bottom plan view in FIG. 2. Since such group assemblies of four stacks of contact springs are identical, only one will be described in detail hereinafter, and such description will sufiice for all such assemblies.

Resuming now the more detailed description, the present switching mechanism comprises a plurality of spaced vertical primary support plate members 18 (FIGS. 2, 3 and 4), which may be of any suitable structural metal, secured to the under side of the keyboard plate 14 by means of screws 20, two of such plates 18 being used to support each of the above mentioned groups of four stacks of contact members. The plates 18 are each provided with three laterally spaced vertical slots 22, the outermost of such slots receiving rigid plate members 24 and 24 of electrical insulating material, and the intermediate slot 22, which is located a short distance from the slot accommodating the plate 24, also receives a rigid plate member 24 of electrical insulating material. Each of the insulating plates 24, 24 has a pair of notches spaced along the upper edge thereof which engage the support plates 18, this engagement being maintained in each case by a rectangular wire 26 inserted between the lower edge of the plates 24, 24' and the bottom of the respective slots 22.

The plates 24 are each provided with four rows of six vertically spaced generally rectangular apertures 28 (FIG. 7), and the strip 24' is provided with a similar arrangement of generally elliptically shaped apertures 28' (FIG. 6) for accommodating the spring contact members 30 in a manner to be more fully described hereinafter.

The support plates 18 are each provided substantially at their midpoints with an additional vertical slot 32 which receives a rigid plate member 34 of electrical insulating material, this plate member likewise having four rows of six vertically spaced generally rectangular apertures 36 (FIG. 9) for accommodating the contact members 30. The plate 34 is also provided with a pair of spaced notches, indicated at 38, along its upper edge which engage the support plates 18, this engagement being also maintained by a rectangular wire 26 inserted between the lower edge of the plate 34 and the bottom of the slot 32.

The insulating plate 34 is formed with a pair of vertically disposed, elongated, spaced ribs or bosses 40, on one of its surfaces, one of which bosses being shown in FIGS. 3, 4 and 9, the slots 32 in the plates 18 being enlarged, as at 42, to accommodate the bosses 40 in the assembly. A plurality of vertically spaced, horizontal apertures 44, corresponding in number to the apertures 36, are formed in the bosses 40 to one side of the surface of the plate 34 (FIG. 10), the axes of the apertures 44 being parallel to the adjacent surface of the plate 34. The apertures 44 are adapted respectively to receive bus bars 46, and, as shown in FIG. 9, the upper limits of the apertures 44 are sufficiently below the upper limits of the corresponding apertures 36 that the upper surfaces of the bus bars are disposed respectively below the contact members 30 and normally spaced therefrom.

The spring contact members 30, which are preferably made of spring bronze, are in the form of thin leaves having parallel long sides, and are so proportioned relatively to the apertures 28, 28, and 36 in the several insulating plates that they may be slipped through such apertures from the left (FIGS. 3 and 4), the contact members being held against retraction by engagement of a notch 48 at one end of the springs with the plate 24' (FIG. The end of the spring contact member containing the notch 48 has a longitudinal slot 50 formed therein so that the end of the spring member may temporarily bend inwardly to allow the split ends to spring outwardly and cause engagement of the notch 48 with the plate 24'. The upper limits of the slots 36 in the plate 34 are all somewhat below the lower limits of the corresponding slots 28 which provide the supports for the several contact members 30 (the respective slots 28 of each plate 24 being at about the same level), so that when the contact members 30 are positioned in the respective slots, they are all bowed downwardly substantially in the center by engagement with the upper limits of the slots 36 of the plate 34 (FIGS. 3 and 4), and are thus resiliently biased respectively upwardly against the upper limits of such slots 36. Since the slots 44 in the bosses 40 are respectively below the corresponding slots 36, the bus bars 46 are positioned normally out of contact with the contact members 30 (FIGS. 8 and 9). Each stack of spring contact members 30 contained in the aligned vertical rows of apertures 28, 28, and 36 comprises, in

4 conjunction with the stack of bus bars 46, a multiplecontact switch, and it will be noted that the plate member 34 which is used with each group of four stacks of contact members 30, and which supports the stack of bus bars, is disposed transversely of such stacks of contact members and substantially in the center thereof.

The insulating plates 34 are formed along one side with a plurality of notches 52, the openings of which are restricted by projections 54, and the vertical dimension of such restricted openings being slightly larger than the vertical dimension of the bus bars 46. The bottoms of the projections 54 are, respectively, slightly below the upper limits of the slots 44. The bus bars 46 are each provided with two bends adjacent one of their ends to provide short, transverse stepped portions 56 (FIG. 10) which are adapted, respectively, to fit in the notches 52 behind the projections 54. By this arrangement a bus bar may be slipped from the left (FIG. 9) through the apertures 44 in the bosses 40 of the respective plates 34 used with the several groups of four stacks of spring contact members, and the end of the bus bar may be momentarily flexed slightly 'downwardly to bring the stepped portion 56 behind the projection 54- in the plate 34 used with the group of four contact members 30 forming one end of the entire switch assembly comprising three such groups, whereby the bus bars are secured against accidental longitudinal displacement.

Referring again more particularly to FIGS. 2, 3, 4, and 8 for a detailed description of the chord button assembly, a structural plate member 58, preferably fabricated of a suitable rigid plastic material, is provided at the bottom of each group 16 of four stacks of spring contact members 30, the plate member 58 having opposed pairs of notches which receive edges 60 of the adjacent plate members 18 used in fabricating one of such groups, the plate 58 abutting the bottom central edges of the plates 18. A similar rigid structural plate member 62 is provided at the top of each of such groups of four stacks of contact springs, the plate 62 having notches to receive opposed pairs of inwardly facing edges 64 adjacent the tops of the plates 18.

The main support plate members 18 are provided along their top and bottom edges with spaced slots 66 having rectangular widened central portions 68, and nuts 70 are inserted in such central portions 68, the nuts 70 having opposed outwardly directed notches for receiving the edges of the plate 18 bordering the central portion 68 of the slots. As will be apparent, the nuts 70 are initially inserted diagonally half-way through the portions 68 until the notches in the nuts are aligned with the edges of the plate 18, and are then brought to a position in which the axis of the nut is parallel to the longitudinal axis of the slot 66, whereby the notches of the nut engage such edges of the plate 18 and are thus restrained against rotation.

Under the lower plate member 58 is an 8-point spring member 72 of any suitable sheet spring material, such as spring bronze, and under the latter is a retaining strip 74, all of these elements being secured to the said plate 58 by means of screw bolts 75 threaded into the nuts 70. Similar bolts 75 and nuts 70 are used to secure the upper plate 62 to the tops of the support plates 18 In the preferred embodiment shown, the spring member 72 is of unitary construction, substantially rectangular in outline, and stamped from a single sheet of metal, and is provided with two pairs of opposed leaf springs 76 (FIG. 2) on each side of the axis of the spring memher running parallel to the contact springs 30. The spring member 72 is so proportioned that when assembled in the switching mechanism, four of such individual leaf springs 76 are in alignment with each stack of six contact members 30.

The lower plate member 58 is provided with four rows of spaced slots 78 (FIG. 8), each row having four such slots and the slots are disposed respectively over the individual leaf springs 76 and adjacent the ends thereof. The upper plate member 62 is likewise provided with four rows of spaced slots 80, similar to the slots 78, and aligned respectively with the latter.

Each of the chord buttons 12 is wedged or adhesively secured to the upper end of a flattened switch actuating slide member 82, preferably stamped from sheet stock of steel or any other suitable metal, which passes loosely through one of the slots '80 in the upper plate 62 and through a corresponding slot 78 in the lower plate 58. The portion of the slide members 82 between the plates 58 and 62 is generally C-shaped, providing a rectangular recess 84 on one side thereof, and each such slide member has fixed thereto by rivets 86 a plate member 88 of rigid insulating material which preferably projects a short distance into the opening 84 from all borders of the opening. Each slide member 82 and its associated plate member 88 together form a switch actuating memher, the plates 88 having integral lugs 90 which project substantially across the recesses 84 of the respective slide members 82, and the lugs 90 each being positioned normally above one of the contact members 30, but spaced therefrom. As will appear more fully hereinafter, the lugs 90 are effective, when the respective chord buttons 12 are depressed, to move the contact members beneath the lugs into contact with their respective bus bars, whereby the tone signals carried by the contact members 30 are conveyed to the bus bars 46. As shown in FIG. 8, when a switch actuating member is intended to engage the uppermost contact member 30, the uppermost lug 90 may merge into the upper portion of the plate member 88 and thus simply provide a horizontal edge of the member 88 which extends downwardly into the rectangular recess 84 of the slide member 82. To assure a good electrical contact between the spring contact members and the bus bars, a short palladium wire 92 is welded to the under side of each contact member 30 above the bus bar (FIG. 9), and similar wires (not shown) may be welded to the tops of the bus bars 46 for engagement with such wires 92.

In order that all of the chord buttons 12 may effectively cause the contact members 30 with which they are respectively associated to contact the respective bus bars by depressing the chord b-utons substantially through equal distances, and at the same time to provide a proper spacing of the chord buttons from each other for expeditious manipulation, the actuator slide members 82 are each formed adjacent their upper ends with two substantially 90 angles to form a gooseneck therein, and a pair of such actuator slides of each group of four associated with each stack of spring contact members is positioned on each side of the stack of bus bars 46 and arranged respectively so that the goosenecks therein place the portions of such actuator slide members between the plates 58 and 62 very close together, while leaving their respective chord buttons 12 comfortably spaced for manipulation by the player. (FIGS. 3 and 4). By this arrangement, the openings 84 in the actuator slides 8-2 forming such pairs will face in opposite directions when identical actuator slide members are used for all chord buttons.

The stack of bus bars is disposed substantially equidistantly from the support plates 24 which support the spring contact members, and the pairs of actuator slides 82 are disposed near the center of the stack of contact members relative to the supports therefor provided by the plates 24, and substantially equidistantly from the bus bars, whereby the distances the chord buttons are depressed for effecting engagement of their associated contact members 30 with the bus bars are substantially equal, and the pressure necessary for manipulating the several chord buttons is also substantially the same for all buttons. In general, an actuator slide member (including the lug-carrying plate 88) on one side of the stack of bus bars will be substantially the same distance from the stack of bus bars as another actuator slide member on the opposite side of such stack which is associated with the same stack of contact members 30.

A layer of soft resilient material 94, such as a conventional polyurethane foam, is placed between the keyboard plate 14 and the top insulating plate 62. The leaf springs 76, which bear against the lower ends of the actuator slides 82, bias the latter upwardly, the combined effects of the resilient material 94 and leaf springs 76 serving to maintain the chord buttons normally in their uppermost positions and also serving to provide the desired cushioning and to maintain substantially equal actuating pressure for the chord buttons. Such uppermost position of the chord buttons 12 is determined by the shoulders 96 on the associated actuator slide members 82 which are adapted to abut the lower surface of the upper plate 62. The downward movement of the actuator slide members 82 is limited by similar shoulders 98 adjacent the bottom of the slide members, which are adapted to abut the upper surface of the lower plate 58.

In assembling the complete switch, the three groups of four stacks of contact members 30 are separately made, and these are then secured side by side to the under side of the keyboard plate 14. In assembling each of such groups, the upper plate 62 is fastened to the support plates 18 in the manner previously described, and the upper ends of the actuator slide members 82 (to which the plates 88 have been riveted) are inserted through the slots in the plate 62 and through suitable openings in the resilient layer 94. Thereafter, the lower plate 58 is secured to the bottoms of the plates 18 as previously described, with the lower ends of the actuator slides 82 projecting through the slots 78 in such lower plate. The insulating plates 24, 24' and 34 are then inserted in their respective slots and secured therein by the wires 26, after which the spring contact members 30 may be placed in the switching device by slipping the contact members endwise through the apertures 28', 28 and 36 in the insulator strips 24', 24 and 34 and through the rectangular recesses 84 of the actuator slide members associated with the particular stack of contact members. The contact members 30 are inserted from the left, as viewed in FIG. 4, until the notches 48 engage insulating strip 24'.

After three such groups of four stacks of contact members have been made, as just described, and secured to the keyboard plate 14, the bus bars 46 may be inserted through the apertures 44 of the several plates 34, and secured against accidental longitudinal movement by hooking the stepped portion 56 thereof behind the projections 54 of the plate 34 used for the end group of contact members. The single stack of bus bars 46 serves all twelve stacks of contact members.

The contact members 30 are provided at their ends adjacent the locking notches 48 with notches 100 for convenient attachment of lead wires 182 which are adapted to be connected to electrical tone signal generators of any suitable form, such as those described in the above mentioned Hanert patent. Lead wires 104 are likewise conncted to the respective bus bars 46 to conduct electrical tone signals therefrom to the instrument output section which may also be of conventional design, such as that described in the said Hanert patent.

The spring contact members 30 are all identical, as are, respectively, the actuator slides 82, the main support plates 18, and the plate members 24. The upper and lower plate members 58 and 62 are also identical, and each one of the four actuator plate members 88 comprising the set associated with a stack of contact members 30 has an identical counterpart in every other such set associated with the other stacks of contact members. Thus, the major portion of the present switching mechanism may be made by assembling together members of a small number of groups of identical parts.

All of the chords in each key to be produced by the illusrtated embodiment of the chord selecting mechanism are capable of being produced by using only six tones of the twelve which make up the even tempered scale, and accordingly, the contact members 30 of each stack thereof adapted to be actuated by the four chord buttons 12 for selecting the chords in a particular key are connected respectively to the six electrical tone signal generators necessary for making up such chords. Twelve terminals 106 are provided (FIG. 2) which are connected respectively, through suitable resistors 108, to the twelve generators (not shown) providing the required twelve tone signal frequencies.

The selection of the six tone signal generators to be connected to each of the twelve stacks of spring contact members 30 will of course be apparent to those skilled in the art, and accordingly, such connections for only one stack of such contact members, and a single actuator slide therefor, are illustrated schematically in FIG. 11, such description sufricing to illustrate all such actuator slides as well as the tone signal generator connections for all such stacks of contact members.

In FIG. 11 the single stack of contact members 30 schematically illustrated is for that stack to be used in producing the major, minor, seventh, and diminished chords for the key of Db, and the particular actuator plate or element 88 depicted is that carried by the actuator slide 82 attached to the chord button corresponding to the key of Db major. Below the spring contact members 30 are the respective bus bars 46, the latter being normally separated from the contact members. The spring contact members 30 are connected respectively to the tone signal generators needed to produce all of the above mentioned chords in the key of Db, such connections being to the Db, Ab, F, G. E, and B tone signal generators. As shown in FIG. 8, the horizontal edge of the plate 88 of insulating material, which projects downwardly into the rectangular rdecess 84 of the actuator slide 82, and which constitutes the uppermost lug 90, is adapted to contact and depress the uppermost contact member 30 when the chord button 12 for Db major is depressed, and other lugs 90 at the same time are adapted to contact and depress the third and fifth contact members 30 from the top. Thus, when the Db major chord button 12 is depressed against the resilient contact members 30 and against the restraining action of its associated leaf spring 76 (FIG. 4) the contact members 30 affected by their actuator slide member 82, 88 (which contact members are connected to the Db, Ab, and F tone signal generators) are brought into contact with their respective bus bars 46, whereby such tone signals are delivered to the output of the instrument where they are combined, amplified, and played through a conventional loud speaker in well known manner. In similar fashion, all the other eleven stacks of spring contact members 30 are connected to the tone signal generators necessary for producing .such chords for all the other keys, and actuator slide members 82, 88 are provided with their lugs 90 suitably placed with respect to the spring contact members, so that upon depression of the chord button 12 for the particular chord desired, the proper combination of tone signals is conducted through the affected contact members 30 to their respective bus bars 46, and thence to the electroacoustical translating output means of the instrument.

It will be understood that the spring contact members need not be horizontally disposed but may be disposed at any angle to the horizontal, and in some such cases the supports provided by the insulating plates 24 may be considered to act as abutments for the spring contact members near their ends.

When an even number of actuator slides 82 is associated with the stacks of contact members 30', one-half of such slides are preferably used on each side of the stack of bus bars, as shown herein. When an odd number of such actuator slides is used, an extra actuator slide will, of course, be disposed on one side of the stack of bus bars. In any event, the actuator slides on each side of the stack of bus bars are preferably brought as close together as possible by means of the described gooseneck arrangement near their upper ends, and all such actuator slides are preferably arranged so as to engage the spring contact members 30 near the centers thereof, and actuator slides one one side of the stack of bus bars are respectively preferably substantially the same distance therefrom as corresponding ones of the actuator slides on the opposite side of the stack of bus bars.

While I have shown and described a particular embodiment of my invention, it will be apparent that numerous modifications and variations may be made without departing from the underlying principles of the invention. I therefore desire, by the following claims, to include within the scope of the invention all such modifications and variations by which substantially the results thereof may be obtained by substantially the sameor equivalent means. i

What is claimed is:

1. For use in an electrical musical instrument including tone signal generators for generating collectively electrica-l tone signals corresponding to the twelve tones of the even tempered scale, and an output system. including electroacoustical translating means, a multiple contact switch comprising a plurality of spaced spring contact members arranged in a stack, said contact members being adapted to be connected respectively to different ones of said tone signal generators, said contact members being supported adjacent their ends on insulating supports, an insulating support plate disposed vertically substantially in the center of said stack and transversely thereof, said support plate having apertures therein for passage of said contact members, a stack of spaced bus bars supported by said support plate, said bus bars corresponding in number to the number of said contact members, said bus bars being adapted to be connected to said electroacoustical translating means, said bus bars being disposed respectively adjacent said contact members and spaced therefrom, at least one manually operable switch actuating member disposed on each side of said stack of bus bars and near the center of said stack of contact members relative to the supports of the latter for selectively moving different combinations of said contact members into engagement with their respective bus bars, said actuating members on one side of said stack of bus bars being substantially the same distance therefrom as the corresponding actuating members on the opposite side thereof, whereby such different combinations of said contact members may be engaged with their respective bus bars upon movement selectively of said actuating members through substantially equal distances.

2. For use in a chord organ including an accordion type button keyboard having a number of rows of buttons for manual selection of chords, tone signal generators for generating collectively electrical tone signals corresponding to the twelve tones of the even tempered scale, and an output system including electroacoustical translating means, a multiple-contact switch comprising a pl urality of spaced leaf spring contact members arranged in a stack, said contact members being adapted to be connected respectively to different ones of said tone signal generators for generating tone signals necessary for producing a plurality of different chords in a given key, said contact members being supported adjacent their ends on insulating supports, an insulating support plate disposed vertically substantially in the center of said stack and transversely thereof, said support plate having apertures therein for passage of said contact members, a stack of spaced bus bars supported by said support plate, said busbars corresponding in number to the number of said contact members and being adapted to be connected to said electroacoustical translating means, said bus. bars being disposed respectively adjacent said contact members and spaced therefrom, at least one manually operable switch actuating member disposed on each side of said stack of bus bars and near the center of said stack of contact memers rela ive to the supports for the latter for selectively moving different combinations of said contact members into engagement with their respective bus bars, said actuating members each including a slide portion, upper and lower structural plate members disposed respectively above and below said stack of said contact members and having aligned guide slots for accommodating said slide portions, said slide portions being disposed respectively in said aligned slots, the upper ends of said slide portions being attached respectively to said buttons of one of said rows, said actuating members on one side of said stack of bus bars being substantially the same distance therefrom as the corresponding actuating members on the opposite side thereof, whereby such different combinations of said contact members may be engaged with their respective bus bars upon movement selectively of said actuating members through substantially equal distances.

3. For use in a chord organ including an accordion type button keyboard having a number of rows of four buttons for manual selection of chords, tone signal generators for generating collectively electrical tone signals corresponding to the twelve tones of the even tempered scale, and an output system including electroacoustical translating means, a pair of spaced vertical structural members, a pair of multiple-contact switch members each comprising six spaced leaf spring contact members arranged in a stack, said stacks being disposed side by side, said contact members of each stack being adapted to be connected respectively to different ones of said tone signal generators for generating tone signals necessary for producing four chords in two different keys, said contact members being supported adjacent their ends on insulating supports carried by said structural members, an insulating support plate supported by said structural members and disposed vertically substantially in the center of said stacks relative to said supports and transversely of said stacks, said support plate having apertures therein for passage of said contact members, the upper limits of said apertures being respectively below the level of the corresponding ones of said first mentioned supports whereby said contact members are bowed downwardly respectively substantially at their midpoints, said support plate having an elongated boss extending vertically on one surface thereof adjacent the said apertures associated with one of said stacks, said boss having six spaced, horizontal apertures therein parallel to the surface of said support plate, a bus bar extending through each of said last mentioned apertures to form a stack of said bus bars, said bus bars being adapted to be connected to said electroacoustical translating means, the upper surface of each of said bus bars being disposed below and spaced from said respective contact members of each of said stacks thereof, a pair of manually operable switch actuating members disposed on each side of said stack of bus bars for each of said stacks of contact members for selectively moving different combinations of said contact members of each stack of the latter into engagement with their respective bus bars, each of said pairs of switch actuating members being disposed near the said center of said stacks of contact members, said actuating members each including a slide portion, upper and lower structural plate members supported by said vertical structural members and disposed respectively above and below said stacks of contact members, said structural plate members having aligned guide slots for accommodating said slide portions, said slide portions being disposed respectively in said aligned slots, the upper ends of said slide portions associated with each of said stacks of contact members being attached respectively to the said key buttons of one of said rows thereof with each of said pairs of slide portions on one side of said stack of bus bars being connected to adjacent key buttons at one end of said one row, said slide portions of each said pair being formed, between said upper structural plate and their respective buttons, with outwardly opposed gooseneck portions whereby said slides of each of said pairs are maintained closer together than are their associated key buttons, the lower ends of said slide portions associated with both of said stacks of contact members projecting below said lower structural plate member, spring means engaging said lower ends to bias said slide portions upwardly, and means for limiting longitudinal movement of said slide portions in said slots.

4. A device in accordance with claim 3, wherein said spring means comprises a unitary stamping of spring metal stock in sheet form generally rectangular in outline and provided with two pairs of opposed leaves on opposite edges, and said stamping is secured to said lower structural plate portion with said leaves along one of said edges being aligned with one of said stacks of contact members and engaging the lower ends, respectively, of said slide portions associated with said one stack of contact members, and the said leaves along the other of said edges being aligned with the other of said stacks of contact members and engaging the lower ends respectively of said slide portions associated with the other of said stacks of contact members.

5. A switching mechanism comprising a plurality of stacks of spaced resilient electrical contact members, each of said contact members being supported at two longitudinally spaced points, said support points for all said contact members being substantially equally spaced, a bus bar associated with corresponding ones of said contact members in all of said stacks and normally spaced respectively from such con-tact members, said bus bars extending transversely of said stacks and substantially midway between opposed pairs of said supports, a plurality of actuating members associated with each of said stacks and engageable with different combinations of said contact members for moving such contact members into engagement with their respective bus bars, said actuating members associated with each said stack being situated on both sides of said bus bars and in proximity to the latter, said actuating members on one side of said bus bars being substantially the same distance therefrom as corresponding ones of said actuating members on the opposite side of said bus bars.

No references cited. LOUIS J. CAPOZI, Primary Examiner. 

1. FOR USE IN AN ELECTRICAL MUSICAL INSTRUMENT INCLUDING TONE SIGNAL GENERATORS FOR GENERATING COLLECTIVELY ELECTRICCAL TONE SIGNALS CORRESPONDING TO THE TWELVE TONES OF THE EVEN TEMPERED SCALE, AND AN OUTPUT SYSTEM INCLUDING ELECTROACOUSTICAL TRANSLATING MEANS, A MULTIPLE CONTACT SWITCH COMPRISING A PLURALITY OF SPACED SPRING CONTACT MEMBERS ARRANGED IN A STACK, SAID CONTACT MEMBERS BEING ADAPTED TO BE CONNECTED RESPECTIVELY TO DIFFERENT ONES OF SAID TONE SIGNAL GENERATORS, SAID CONTACT MEMBERS BEING SUPPORTED ADJACENT THEIR ENDS ON INSULATING SUPPORTS, AN INSULATING SUPPORT PLATE DISPOSED VERTICALLY SUBSTANTIALLY IN THE CENTER OF SAID STACK AND TRANSVERSELY THEREOF, SAID SUPPORT PLATE HAVING APERTURES THEREIN FOR PASSAGE OF SAID CONTACT MEMBERS, A STACK OF SPACED BUS BARS SUPPORTED BY SAID SUPPORT PLATE, SAID BUS BARS CORRESPONDING IN NUMBER TO THE NUMBER OF SAID CONTACT MEMBERS, SAID BUS BARS BEING ADAPTED TO BE CONNECTED TO SAID ELECTROACOUSTICAL TRANSLATING MEANS, SAID BUS BARS BEING DISPOSED RESPECTIVELY ADJACENT SAID CONTACT MEMBERS AND SPACED THEREFROM, AT LEAST ONE MANUALLY OPERABLE SWITCH ACTUATING MEMBER DISPOSED ON EACH SIDE OF SAID STACK OF BUS BARS AND NEAR THE CENTER OF SAID STACK OF CONTACT MEMBERS RELATIVE TO THE SUPPORTS OF THE LATTER FOR SELECTIVELY MOVING DIFFERENT COMBINATIONS OF SAID CONTACT MEMBERS INTO ENGAGEMENT WITH THEIR RESPECTIVE BUS BARS, SAID ACTUATING MEMBERS ON ONE SIDE OF SAID STACK OF BUS BARS BEING SUBSTANTIALLY THE SAME DISTANCE THEREFROM AS THE CORRESPONDING ACTUATING MEMBERS ON THE OPPOSITE SIDE THEREOF, WHEREBY SUCH DIFFERENT COMBINATIONS OF SAID CONTACT MEMBERS MAY BE ENGAGED WITH THEIR RESPECTIVE BUS BARS UPON MOVEMENT SELECTIVELY OF SAID ACTUATING MEMBERS THROUGH SUBSTANTIALLY EQUAL DISTANCES. 